Cross-kingdom interactions matter: fungal-mediated interactions structure an insect community on oak

Abstract

Although phytophagous insects and plant pathogens frequently share the same host plant, interactions among such phylogenetically distant taxa have received limited attention. Here, we place pathogens and insects in the context of a multitrophic-level community. Focusing on the invasive powdery mildew Erysiphe alphitoides and the insect community on oak (Quercus robur), we demonstrate that mildewinsect interactions may be mediated by both the host plant and by natural enemies, and that the trait-specific outcome of individual interactions can range from negative to positive. Moreover, mildew affects resource selection by insects, thereby modifying the distribution of a specialist herbivore at two spatial scales (within and among trees). Finally, a long-term survey suggests that species-specific responses to mildew scale up to generate landscape-level variation in the insect community structure. Overall, our results show that frequently overlooked cross-kingdom interactions may play a major role in structuring terrestrial plant-based communities.

Keywords

Erysiphe alphitoides; indirect defence; indirect interactions; invasive species; Microsphaera alphitoides; multi-trophic interactions; plant-fungus-insect interactions; trait-mediated interactions; tripartite interactions

Published in

Ecology Letters
2012, Volume: 15, number: 3, pages: 177-185 Publisher: WILEY-BLACKWELL

UKÄ Subject classification

Ecology


Publication identifier

DOI: https://doi.org/10.1111/j.1461-0248.2011.01724.x

Permanent link to this page (URI)

https://res.slu.se/id/publ/85055